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Select up to 4 generators to compare specs, power output, noise levels, runtime and more. Your compare URL is shareable.

  • Firman T04073
  • Aceup Energy AI2500S
  • Model T04073
    Model T04073

    Firman 4,000W Tri-Fuel Generator

    4000W
    Running
    67 dB
    Noise
    View details
  • Model AI2500S
    Model AI2500S

    Aceup Energy 1,900W Gas Inverter Generator

    1900W
    Running
    58 dB
    Noise
    View details
Quick charts
Each chart uses its own Y-axis scale (so numbers are comparable within a chart).
Running watts
W
Starting watts
W
Noise
dB
Runtime @50%
h
Running watts by fuel
Shows how output changes across gasoline/propane/natural gas (when available).
Generator Specifications Comparison
SpecificationFirman T04073Aceup Energy AI2500S
General
Product type
Generator
Not available
Fuel
Tri-Fuel
Gasoline
InverterNoYes
Parallel capableNoYes
RV readyNoYes
Running watts
Winner: Winner: 4000 W
1900 W
Starting watts
Winner: Winner: 5000 W
2500 W
Noise (lower limit)
67 dB
Winner: Winner: 58 dB
Weight
123.4 lbs
Winner: Winner: 44 lbs
Run time @50% load
Winner: Winner: 12 h
Not available
Run time @25% load
14 h
10 h
Fuel tank
5 gal
1.32 gal
Fuel gaugeYesNo
Approx. dimensions (L × W × H)
29.8 x 27.5 x 26.1
Not available
Electrical
Voltage (AC)
120/240
120V
Voltage (DC)
Not available
12V
GFCI outletsYesNo
Covered outletsYesNo
Automatic Voltage RegulationYesNo
THD
11%-14% %
1.5 %
Engine
Engine
223 cc OHV 4-stroke, cast iron sleeve
79.8cc 4-Stroke OHV Engine
Alternator
Not available
Not available
Starting system
Recoil, Electric
Recoil Start
Warranty
Warranty
3 years
2 years
Power by fuel
GasolineNot availableNot available
Running watts
4000 W
1900 W
Starting watts
5000 W
2500 W
Running amps (120V)
Not available
Not available
Running amps (240V)
Not available
Not available
Peak amps (120V)
Not available
Not available
Peak amps (240V)
Not available
Not available
Run time @50% load
14 h
Not available
Run time @25% load
Not available
10 h
Natural gasNot availableNot available
Running watts
3200 W
Not available
Starting watts
4000 W
Not available
Running amps (120V)
Not available
Not available
Running amps (240V)
Not available
Not available
Peak amps (120V)
Not available
Not available
Peak amps (240V)
Not available
Not available
Run time @50% load
Not available
Not available
Run time @25% load
Not available
Not available
PropaneNot availableNot available
Running watts
3600 W
Not available
Starting watts
4500 W
Not available
Running amps (120V)
Not available
Not available
Running amps (240V)
Not available
Not available
Peak amps (120V)
Not available
Not available
Peak amps (240V)
Not available
Not available
Run time @50% load
9 h
Not available
Run time @25% load
Not available
Not available
Other
Data center
Not available
Not available
Indicators
true
true
Compliance
CARB, EPA, ANSI/PGMA G300-2023
EPA Compliant
Security
Not available
Not available
Spark arrestorYesNo
Neutral
true
Not available
UPC
840876140734
Not available
Core / High-priority specs
Running Watts (Gasoline)
4000
1900
Running Watts (Propane)
3600
Not available
Running Watts (Natural Gas)
3200
Not available
Starting Watts (Gasoline)
5000
2500
Starting Watts (Propane)
4500
Not available
Starting Watts (Natural Gas)
4000
Not available
Runtime @ 50% Load (Gasoline)
14
Not available
Runtime @ 50% Load (Propane)
9
Not available
Runtime @ 25% Load (Gasoline)
Not available
10
AC Outlet Types
1x Duplex 120V 20A (5-20R) GFCI; 1x 120V 30A (L5-30R); 1x 120/240V 30A (L14-30R)
One 120V 5-20R 20A Outlet
Electrical & power
Frequency
60
60
Engine & construction
Engine Type
223 cc OHV 4-stroke
4-Stroke OHV
Engine Displacement
223
79.8
Cylinder Sleeve
cast iron
Not available
Runtime & fuel system
Runtime @ 25% Load (Gasoline)
Not available
10
Runtime @ 50% Load (Gasoline)
14
Not available
Runtime @ 50% Load (Propane)
9
Not available
Controls & display
Display Type
Not available
Intelligent Gauge
Idle Control System
Not available
Eco Mode
Safety & compliance
Overload Protection System
Low oil and overload protection, CO monitoring
Not available
Low Oil ProtectionYesNo
Carbon Monoxide MonitoringYesNo
Included equipment
Starting Components
Recoil, Electric
Not available
Included Accessories
Oil, funnel, tool kit, propane hose, RV adapter, cover, battery, and wheel kit
Not available
Warranty & identification
Residential Warranty
Not available
2
Commercial Warranty
3
Not available
Part Number
Not available
AI2500S
Additional specs
Summary
The Firman T04073 is a 4,000-watt tri-fuel generator that runs on gasoline, propane, or natural gas. On gasoline, it delivers 5,000 starting watts and 4,000 running watts, enough to power a refrigerator, microwave, and multiple household circuits simultaneously. On propane, output drops to 3,600 running watts, and on natural gas it falls to 3,200 running watts. This fuel flexibility means users can switch between sources based on availability and cost, a significant advantage during extended outages or in remote locations where one fuel type may be scarce. The T04073 targets homeowners, RV owners, and job site operators who need reliable backup power without the commitment to a single fuel source. Its 5-gallon tank runs for 14 hours at 25% load on gasoline, translating to roughly one week of emergency backup if you run it a few hours per day. The unit includes a wheel kit, making it easier to position despite its 123.4-pound weight.
The Aceup Energy AI2500S is a gasoline-powered inverter generator with a rated wattage of 1900 watts and a peak wattage of 2500 watts.
  • Most Powerful
    Firman T04073
    4000W running
  • Quietest
    Aceup Energy AI2500S
    58 dB
  • Longest Runtime
    Firman T04073
    12h at 50% load
Where to buy
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Firman T04073
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Aceup Energy AI2500S
Store links
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